In "Father's Day" in season 1 of DW, the young Rose was played by a girl name Julia Joyce.
I just watched a BBC movie called The Ruby in the Smoke (based on a book by Philip Pullman) and staring Billie Piper as Sally. In a flashback in the movie you see a shot of young Sally. And I said to myself "Self, that girl looks familiar. Didn't she play young Rose in DW?" So I went a looked. And she did. Aren't I good? She also does the same thing again in the most recent remake of Mansfield Park (Billie plays Fanny). I think she's possibly been type-cast. :D